16919548781 has 4 divisors (see below), whose sum is σ = 16920690492. Its totient is φ = 16918407072.

The previous prime is 16919548777. The next prime is 16919548799. The reversal of 16919548781 is 18784591961.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18784591961 = 1787 ⋅10511803.

It can be written as a sum of positive squares in 2 ways, for example, as 3535372681 + 13384176100 = 59459^2 + 115690^2 .

It is a cyclic number.

It is not a de Polignac number, because 16919548781 - 2² = 16919548777 is a prime.

It is a super-2 number, since 2×16919548781² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16919548781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16919548771) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 548330 + ... + 578363.

It is an arithmetic number, because the mean of its divisors is an integer number (4230172623).

Almost surely, 2^16919548781 is an apocalyptic number.

It is an amenable number.

16919548781 is a deficient number, since it is larger than the sum of its proper divisors (1141711).

16919548781 is a wasteful number, since it uses less digits than its factorization.

16919548781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1141710.

The product of its digits is 4354560, while the sum is 59.

The spelling of 16919548781 in words is "sixteen billion, nine hundred nineteen million, five hundred forty-eight thousand, seven hundred eighty-one".